The invention concerns a tube filling machine comprising a circulating conveying device for transporting a tube through the tube filling machine to pass through differing processing stations. One of the processing stations is a filling unit in which the tube can be filled with a desired product.
Known tube filling machines have a conveying device which is usually designed as an endless belt or endless chain and which has a plurality of receptacles or tube holders for one tube each. The empty tubes are introduced into the tube holders of the conveying device at a feed station and pass several work stations including, in particular, a filling unit and a subsequent closing unit. In the filling unit, the tubes are filled via a filling pipe which is connected to a filling medium supply via a metering means, and are filled with the desired product or medium. The filled tube is then further transported to the closing unit in which the upper tube end is closed.
If, following filling of a first product or medium in a tube filling machine, another product or medium is to be filled, the filling unit must, for hygienic reasons, be completely cleaned of the remains of the first product. This is usually effected by removing the filling unit from the tube filling machine and cleaning it at an external location. To remove the filling unit, the mounting screws which hold the filling unit in the tube filling machine must first be unscrewed. Subsequently, the filling and metering element drives, i.e. usually the rotary valve drive and the shut-off tappet drive, must be released from the respective filling and metering elements, i.e. the rotary valve and the shut-off tappet. The filling unit, including all the wet parts soiled by the first product, must then be lifted from the tube filling machine using a hoist, e.g. a crane. Since a tube filling machine must be compact in construction, the space for removal and, in particular, lifting of the filling unit is very limited which makes the removal of the filling unit difficult, time-consuming, and therefore expensive. Moreover, the tube filling machine cannot be operated during removal and during installation of a new filling unit.
It is the underlying purpose of the present invention to produce a tube filling machine of the mentioned type which facilitates removal and installation of the filling unit in a reduced amount of time.
This object is achieved in accordance with the invention in a tube filling machine of the mentioned type in that the filling unit is disposed on a support structure which can be adjusted between an operating position in which the filling unit is located in the tube filling machine above the tube to be filled, and a non-operating position in which the filling unit sidewardly projects out from the tube filling machine.
The invention is based on the fundamental idea of not directly installing the filling unit in the tube filling machine, rather disposal thereof on a special support structure which can be adjusted when necessary. During operation of the tube filling machine, the filling unit is conventionally located above the tubes to be filled, with the support structure being located in the so-called operating position. When the product is to be changed, the support structure is adjusted. It can thereby be sidewardly withdrawn from the tube filling machine, but preferably, the support structure is pivotable such that it can be laterally pivoted out of the tube filling machine. When projecting from the side of the tube filling machine, the support structure is in the so-called non-operating position to provide good access to the filling unit which also projects past the side of the tube filling machine. In this manner, the filling unit disposed on the support structure can be grasped and lifted from the support structure using a conventional hoist, in particular, a crane or fork-lift. Towards this end, a further development of the invention provides a special receptacle for the hoist, which can, in particular, be pipe or rail-like guides for the forks of a fork-lift.
It has been demonstrated that the lateral extension or pivoting of the filling unit considerably decreases its installation and removal times. Consequently, the down times of the tube filling machine during product change are considerably reduced.
Installation or removal of the filling unit can be further accelerated if the drives of the filling and metering elements are automatically decoupled from or coupled to the filling and metering elements during adjustment of the support structure. Towards this end, in a preferred embodiment of the invention, the filling unit comprises a rotary valve and a rotary valve drive which can be automatically decoupled from the rotary valve when adjusting the support structure, and therefore the filling unit, into the non-operating position, and which automatically engages with the rotary valve when adjusting the support structure, and therefore the filling unit, into the operating position. Correspondingly, the filling unit can also comprise at least one shut-off tappet and a tappet drive which can be automatically decoupled from the shut-off tappet when adjusting the support structure, and therefore the filling unit, into the non-operating position, and which automatically engages the shut-off tappet when adjusting the support structure, and therefore the filling unit, into the operating position. The time-consuming release of the connection between the rotary valve and the rotary valve drive or between the shut-off tappet and the tappet drive can therefore be omitted. A further advantage is the fact that the drives can be used for the corresponding filling and metering elements of different filling units, such that each filling unit does not require its own drive means.
In a preferred embodiment of the invention, the support structure comprises a bottom frame and a support arm which is pivotably disposed thereon. An adjustment device is provided between the bottom frame and the support arm. The adjustment means can e.g. be a spindle drive or a piston cylinder unit.